Alfaxalone versus alfaxalone-dexmedetomidine anaesthesia by immersion in oriental fire-bellied toads (Bombina orientalis)

作者：Adami Chiara^*; d'Ovidio Dario; Casoni Daniela

来源：Veterinary Anaesthesia and Analgesia, 2016, 43(3): 326-332.

DOI：10.1111/vaa.12290

• alfaxalone
• anaesthesia
• dexmedetomidine
• immersion technique
• toads

ObjectiveTo determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis).
Study designPilot study followed by a prospective, randomized, experimental trial.
AnimalsFourteen oriental fire-bellied toads.
MethodsThe pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20mg100mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, tobe administered either alfaxalone (group A) oralfaxalone-dexmedetomidine (group AD). After immersion for 20minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5minute intervals and compared statistically between groups. Side effects and complications were noted and recorded.
ResultsIn the pilot study, a dexmedetomidine concentration of 0.3mg100mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A.
Conclusions and clinical relevanceThe addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate thelevel of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures.

• 出版日期2016-5